Development of social technologies leads to increasing power consumption of telecommunications devices; in addition, in order to ensure normal running of a device, a heat dissipation requirement of the device needs to be met. Therefore, a cooling fan with a high rotational speed comes into being. Correspondingly, a higher rotational speed of a cooling fan leads to higher motor power density required by the cooling fan.
A currently efficient side stand magnetic motor is used as an example. The side stand magnetic motor is generally disposed sideways, can implement relatively large power output in relatively small space, and has high practicality. As shown in FIG. 1, a cooling fan using a side stand magnetic motor includes a fan frame 10 and a fan base 12 fixedly connected to the frame 10 using a support bracket 11, where a bearing seat 13 of the fan is fixedly connected to the fan base 12, and the side stand magnetic motor used for sleeving and press-mounting a fan blade 14 is fixedly connected to the bearing seat 13 of the fan. The side stand magnetic motor includes a motor base 15 fixedly connected to the bearing seat 13, and a stator (silicon steel sheet) is fastened on the motor base 15, where the stator includes a tubular body 161 and a coil 162 wound around the body 161, an insulation sheet 163 is disposed on an upper end face and a lower end face of the body 161 and between the body 161 and the coil 162, and the coil 162 is bonded to and fastened on the motor base 15 by means of glue pouring, thereby completing fastening of the stator. A rotor is disposed outside the stator, where the rotor includes a tubular enclosure 171, the fan blade 14 is sleeved outside the enclosure 171, a rotor magnet 172 is fastened inside the enclosure 171, and there is a gap between the rotor magnet 172 and the coil 162 of the stator. After the coil 162 is electrified, the stator can drive the rotor to rotate under the action of magnetic induction, thereby enabling the cooling fan to work normally.
In the prior art, heat generated by a coil is dissipated mainly through a gap between a stator and a rotor. Generally, in order to ensure an electromagnetic induction effect, a gap between the stator and the rotor is generally relatively small, causing a relatively small amount of airflow between the stator and the rotor; therefore, efficiency of heat dissipation through the foregoing gap is relatively low.